/**
*    Copyright (C) 2008 10gen Inc.
*
*    This program is free software: you can redistribute it and/or  modify
*    it under the terms of the GNU Affero General Public License, version 3,
*    as published by the Free Software Foundation.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*    As a special exception, the copyright holders give permission to link the
*    code of portions of this program with the OpenSSL library under certain
*    conditions as described in each individual source file and distribute
*    linked combinations including the program with the OpenSSL library. You
*    must comply with the GNU Affero General Public License in all respects for
*    all of the code used other than as permitted herein. If you modify file(s)
*    with this exception, you may extend this exception to your version of the
*    file(s), but you are not obligated to do so. If you do not wish to do so,
*    delete this exception statement from your version. If you delete this
*    exception statement from all source files in the program, then also delete
*    it in the license file.
*/

#include "mongo/pch.h"

#include "mongo/base/init.h"
#include "mongo/base/status.h"
#include "mongo/bson/util/builder.h"
#include "mongo/client/dbclientinterface.h"
#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/resource_pattern.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/cloner.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/copydb.h"
#include "mongo/db/commands/rename_collection.h"
#include "mongo/db/db.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/index_builder.h"
#include "mongo/db/instance.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/operation_context_impl.h"
#include "mongo/db/storage_options.h"

namespace mongo {

    // SERVER-4328 todo review for concurrency
    // :(
    thread_specific_ptr<DBClientBase> authConn_;

    /* Usage:
     * admindb.$cmd.findOne( { copydbgetnonce: 1, fromhost: <connection string> } );
     *
     * Run against the mongod that is the intended target for the "copydb" command.  Used to get a
     * nonce from the source of a "copydb" operation for authentication purposes.  See the
     * description of the "copydb" command below.
     */
    class CmdCopyDbGetNonce : public Command {
    public:
        CmdCopyDbGetNonce() : Command("copydbgetnonce") { }

        virtual bool adminOnly() const {
            return true;
        }

        virtual bool slaveOk() const {
            return false;
        }

        virtual bool isWriteCommandForConfigServer() const { return false; }

        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {
            // No auth required
        }

        virtual void help( stringstream &help ) const {
            help << "get a nonce for subsequent copy db request from secure server\n";
            help << "usage: {copydbgetnonce: 1, fromhost: <hostname>}";
        }

        virtual bool run(OperationContext* txn,
                         const string&,
                         BSONObj& cmdObj,
                         int,
                         string& errmsg,
                         BSONObjBuilder& result,
                         bool fromRepl) {

            string fromhost = cmdObj.getStringField("fromhost");
            if ( fromhost.empty() ) {
                /* copy from self */
                stringstream ss;
                ss << "localhost:" << serverGlobalParams.port;
                fromhost = ss.str();
            }

            BSONObj ret;

            ConnectionString cs = ConnectionString::parse(fromhost, errmsg);
            if (!cs.isValid()) {
                return false;
            }

            authConn_.reset(cs.connect(errmsg));
            if (!authConn_.get()) {
                return false;
            }

            if( !authConn_->runCommand( "admin", BSON( "getnonce" << 1 ), ret ) ) {
                errmsg = "couldn't get nonce " + ret.toString();
                return false;
            }

            result.appendElements( ret );
            return true;
        }

    } cmdCopyDBGetNonce;

} // namespace mongo
